Electrical machinery



1933. c. A. PARSONS ET AL 1,893,375

ELECTRICAL MACHINERY Filed July 3, 1928 3 Sheets-Sheet 1 2 1 fizz 3 L1- 5 o o a a n a o o o o c o o a o c a u a u o o o a o o a o o a o o u o a on a: no n o a o o o o o a o o0 a a o 0 o n a a o 0c cocoa Jan. 3, 1933. c. A. PARSONS ET AL ELECTRICAL MACHINERY Filed July 3, 1928 3 Sheets-Sheet 2 3 vwemtoz 6 'Jan.3,1933. PARSONS-HAL 1,893,375

ELECTRICAL MACHINERY Filed July s, 1928 s Sheets-Sheet s M iv {KS1 i r \I d V I I I III/I II II 1/ l l/ l KIM Patented Jan. 3, 1933 U TE STATES T N FF CE A CHARLES ALGERNON PARSONS AND JESSEL.ROSEN,' OF NEWCASTLE-UPON-TYNE, ENGLAND, SAI DJROSEN ASSIGNOR .TO SAID. PARSONS; KATHARINE PARSONS, VINCENT THOMPSON AN D FREDERICK GORDON HAY BEDEORD, LEGAL REPRESENTA TIVES 0E SAID CHARLES ALGERNON PARSONS, DECEASED ELECTRICAL macmnnny a Application filed July 3, 1928 Serial No. 290,225, and in Great Britain July 5, 1927.

The invention relates to the ventilation of dynamo-electric machinery, transformers and the like. 1

In modern practice it has become common, particularly in the case of high-speed alternatorsof large output, to employ theclosed circuit system of ventilation, in which the air afterfits passage through the alternator is led to'suitable coolers, the same air being through a plurality of stages of the dynamo-.

electric machine, transformer or the like and is subjected to intermediate cooling between such stages.

.Referring to the accompanying drawm s a v Figure 1 shows a longitudinal View for the most part insection of an alternator cooled in accordance with the present invention,

Figure 2 as regards its left-l1and half being an end view of the alternator shown in Figure 1 and as regards its right-hand half a crosssection on theline 2-2 of Figure '1; Figure 3 shows in longitudinal section to a larger scale a modified form of baflie arrangement,

Flgure 1 being a part cross section on the line 4:-4 of Figure 3, and

Figure 5 a part cross section on the line 5-5 of Figure 3; finally Figure 6 shows a modified form of the invention in cross section. A

Thesame reference symbols are used in the different figures to denote corresponding parts. e The arrows in Figure 1 show the general direction of the circulating air.

In carrying theinvention into effect according to the illustrative form shown in the figures as applied to an alternator with a stationary armature, the coolers,A to A, are arranged in the foundationof the machine and the cooled air issuing therefrom is led by an external inlet passage, B, of which an end shield, G, of the'alternator may form one wall, to an annular duct, D, whence a fan, F, mounted on the rotorv shaft, G, forces it into the spacebetween the end shield, Qand, end .wall, H,iof the dynamo. After cooling the armature endwindings, J, arranged in this space, the cooling air passes through holes, K, in the end wall into the first, L of a series of axially-disposed annular ducts, L to L, which vary in cross section to suitthe build of the machine and encircle corresponding zones or stages, M to M", of armature core sections. These sections throughout the machine. are providedwith passages or ducts,

air gap, 0, and also with axial connecting ducts, P to P so that the cooling air described above is joined in the first annular duct, LT, by other cooling air which has flowed radially outwards through the ducts, T N The two streams of air thus united pass downwardly into a cooler section, A running across the base or foundation of the machine, this cooler being 'ofany standard tube'construction provided withthe usual waterbox or boxes, Q, and so forth. p The first cooler section, A extends axially over the length of thefirst and second annular ducts, L and L so that the'cooled air from the duct, L forced to traverse the cooler by suitable baflies, S then passes into the second annular duct, L and radially "inwards through the passages, N between the core sections, whence it passes byway of the axial passages, P and air gap to the third annular duct, L the third and fourth ducts, L and L corresponding to the first and second and and thence by Way of the corresponding'annular duct, L to a final cooler section, A

arranged alongside those above described.

From this cooler section, the cooled airpasses by way of the inlet passage, B, described above, to repeat the circuit a The cooler should in all cases be arranged so as to prevent any surface condensationbe" 7 mg carried on to the windlngs, while known precautions such as drying make-up air, us-

ing acdry agent in the system or other similar means, can be taken as required.v

v According to a preferred modification as shown in Figures 3, 4:1and 5, however, the

Circumferential baffles, such as R, projecting from the core sections, R R lying rebaifle device consists of a tube, T, preferably. of a non-metallic material, such as presspahn or bakelite, inserted in the stator bore, a small clearance, U, being leftbetween the tube, T,

' {and the rotor, G. The tube, T, takes the form of a solid annulus as indicated in Figure 3 at T in way. of the core section, R and s1m1larlysin wayof the core section, R or wherever I e bafiles are required, but at-other points of its length, the tube, T, is provided with axial holes, T and radial perforations, T

spaced to register with the ducts, N, between the core sections, the air taking the same course through the various ducts asdescribed above with reference to Figure. 1., i V

As shown in Figure 6, the longitudinal per-' forations may be replaced by grooves, T, running longitudinally along the outer surface of the tube,T,'these grooves preferably conformingin breadth with the-configuration of the core sections, M; in some cases, the bottom walls of the groovesmay be perforated as shown at T Such a tubular form of baffle. is strong and,

readily secured in place in the stator bore; moreover, owing toits shape and absence of projections, the rotor can be slid in orout longitudinally Without damage to itself, to the bafile tube, or to the stator. V

Preferably, as described. above, the, circulation is eflected'by means of a fan attached as, described to the rotor shaft and disposed inthe'sp'ace between the end shield and the end wall of the dynamobut separately drivenfans. may be employed, or alternatively fans coupled to the rotor shaft, while in addition any suitable gas may be circulated instead of air.

By virtue of thepresent invention instead of circulating,for example 60,000'cubic feet of air per minute in an alternator withthe methods of cooling hitherto employed and with a total pressure dropvof 5 inches of water, a, much lessvolume of air amounting to, say 10,000 cubic feet per minute with a consequent large: decrease in the size of the path including said ducts.

ducts required, may be employed with a total pressure drop of 22 inches of water, the power required for drivingv the air through the system being thus somewhat lower in compara le cases. 7 l g I Owing tothe reduction in size of the large external ducts, their cost and also the cost of the foundations is reduced in the form of the invention described above;

Although one form of the inventionhas been described in def ail, it will be evident that its scope is wide enough to include many variations as regards, for example, the disposition of the actual cooling passages and coolers,'so long as the ventilating-air or the like is subjected to intermediate cooling on its passagethroughthe machine.

We claim:

1. A'dynamo-electric machine having coaxial stator and rotor members separated. by an air gap, a tube disposed in said gap, said tube being co-axial withthe axis of rotation of the machine and having ducts therein, and

means for circulating a cooling medium in a given path through said machine, the given 2. A dynamo-electric machine having coaxial stator and rotor members separated by an air gap, said stator having a plurality of juxtaposed core sections with ducts therebetween, a tubeco-axial with the axis of'said machine and having ducts in operative juxta position with the ducts of the core sections, and means for circulating a cooling medium throughsaid machine in agiven path include ing the ducts between the sections and the tube ducts. v I v I 3'. 'A- dynamoeelectric machine, having ,coaxial statorand rotor members separated by an air gap, said stator having a pluralityof juxtaposed core sections with radial ducts therebetween, a tube co-axial with the axis of the machine and disposed in. the air'gap, said tube having longitudinally disposed ducts in operative association with the radial duets, said tube having ductless portions forming baflles between the sections, and

means for circulating a cooling medium through the machine in a given. path includ-, ing the ducts betweenthe sections and the tube ducts.

dynamo-electric machine.

6. Ventilating system for a dynamo-electric machine, comprising a stator having a series of core sections and radial passages therebetween, a rotor member disposed within said stator with an intervening air gap, a plurality of juxtaposed ducts surrounding said core sections and in communication with said passages, intercoolers connecting said ducts, said intercoolers being juxtaposed and embodied in a single structure, directing means disposed in said air gap and means for circulating a cooling medium through said passages, said ducts and said intercoolers.

7. A dynamo-electric machine comprising a stator having a series of juxtaposed core sections and passages connectingsaid sections, a rotor member disposed within said stator with an intervening air gap, in combination with means for circulating a cooling medium through said sections in series stages, said circulating means including directing means disposed in said air gap, and cooling means for said medium operatively disposed in relation to said passages at an intermediate point of the flow through said series of sections, said cooling means forming a unit embodied in the structure of the dynamo-electric machine and common to a plurality of said stages.

8. A dynamo-electric machine comprising a stator having a series of juxtaposed core sections and passages connecting said sections and a rotor member disposed within said stator with an intervening air gap, means defining a series path through the core sections, said defining means including directing means disposed in said air gap, means for circulating a cooling medium through said path, and cooling means in said path between sections, the cooling medium passing through the cooling means of alternate sections in different directions, said cooling means forming a unit embodied in the structure of the dynamo-electric machine and common to a plurality of said sections.

9. A dynamo-electric machine comprising a stator having a series of juxtaposed core sections and passages exterior to the core sections connecting said sections, and a rotor member disposed within said stator with an intervening air gap, directing means disposed in said air gap, means for circulating a cooling medium through said sections and passages in series as determined by said directing means in said air gap, the core sections having radial ducts for conducting the cooling medium in parallel, and cooling means for said medium operatively disposed of sections, said cooling means forming a 7 unit embodied in the structure of the dyna- V mo-electric machine and common to a plurality of said sections.

10. A dynamo-electric machine having coaxial stator and rotor members separated by an air gap, means for circulating'a cooling medium in a given path throughsaid machine and air gap, said means including an annulus in said air gap provided with air passages and baflies for directing the cooling.

medium throughthe parts of the machine to be cooled.

11. A dynamo-electric machine having 00 axial stator and rotor members with an intervening air gap, one of said members having a series of core sections and radial passagestherebetween, a plurality of juxtaposed ducts surrounding said core sections, each duct being in communication with'a plurality of said radial passages, and means for circulating a gaseous cooling medium in a given path through said passages and ducts, said circulating means including means disposed in said air gap between said pluralities of radial passages for directing the cooling medium'through the parts of the machine to be cooled.

12. A dynamo-electric machine having co axial stator and rotor members with an intervening air gap, one of said members having a series of core sections and groups of radial passages therebetween,and means for circulating a gaseous cooling medium alternately inwards and outwards through said groups of radial passages, said circulating means including directing means disposed in said air gap. 7

In testimony whereof we have signed our names to this specification.

CHARLES ALGERNON PARSONS.

J ESSEL' ROSEN.

in relation to said passages at an intermediate point of the flow through said series 

